Why and how are some answers deleted?

Answers that do not fundamentally answer the question may be removed. This includes answers that are:

commentary on the question or other answers

asking another, different question

“thanks!” or “me too!” responses

exact duplicates of other answers

barely more than a link to an external site

not even a partial answer to the actual question

If you wish to improve an existing answer, click the edit link beneath it. For more guidance, see How to Answer.

Answers can be deleted at any time by their authors, unless the answer has been accepted by the question asker.

Answers can also be deleted by the community. Moderators can delete any answer, and trusted community members can vote to delete answers scoring -1 or lower (3 votes will result in deletion).

Additionally, any answer that accumulates enough offensive or spam flags will be automatically deleted.

What happens when a post is deleted?

Once a post has been deleted, it will disappear for all users except the post's author, developers, moderators, and users with over 10,000 reputation. However, deleted posts can be undeleted by casting undelete votes. Once a post has 3 undelete votes (more for highly-active questions), it will no longer be deleted.